The invention relates to a device for coating food products with granular material, for example breadcrumb material, comprising a rotating conveyor belt which is permeable to the granular material and on which the food products can be held, guide plates which extend beneath a section of the top part and the bottom part of the conveyor belt, a feed, which opens out above the top part of the conveyor belt, for the granular material, diverter means for guiding the granular material from the top part to the bottom part of the conveyor belt and back, as well as conveyor means for conveying granular material from the top part of the conveyor belt to the feed.
An invention of this nature is known from EP-B-397,267 and U.S. Pat. No. 3,759,218. In the first known device, the bottom part is guided along an S-shaped path in which there is incorporated a buffer with an overflow, via which some of the granular material is conveyed upwards and back to a storage hopper which opens out above the top part of the conveyor belt.
The granular material comprises a mixture of relatively fine and relatively coarse constituents. The relatively fine constituents sink downwards more quickly than the relatively coarse constituents, with the result that during the conveyance of the said material segregation can occur, so that separate layers containing relatively fine and relatively coarse material are formed.
As a result, it is not always readily possible to coat the products in the correct way. For example, it may be desirable to coat the products with relatively coarse material on the top side or the visible side. However, if the relatively fine constituents reach the products first, the adhesion of the relatively coarse constituents is then impaired. The known device has the drawback that the coating process cannot be controlled in the desired way.